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AmityWeb2021's avatar
AmityWeb2021
Copper Contributor
Dec 22, 2021

Trying to find help for 550 5.7.511 Access denied, banned sender

I run a mail server for many business clients of mine. Microsoft have blocked our IP address, so we cant send to Office365 email addresses. I get a bounce back saying:   host cr-studio.mail.protec...
office 365
suportecw's avatar
suportecw
Copper Contributor
We have the same problem!
We can't send mails to Microsoft 365 Exchange, but Outlook.com, live.com, hotmail.com, it's ok!
timbertens's avatar
timbertens
Copper Contributor
Dec 23, 2021

suportecw We have the same problem too.  I've requested delisting via the website but it responds there is no listing for the involved IP.  Next try is send the error message to Email address removed -> but according to the automated response it can take up to 24h 

 

MS found a great way to increase their marketshare it appears ...

  • suportecw's avatar
    suportecw
    Copper Contributor
    Dec 23, 2021
    timbertens this problem is occurring since last Tuesday! Our mail server is Zimbra ZCS, and we have approximately 1200 accounts, that can't send mails to MS 365 Exchange... We are having some troubles and loss with this 😕
    • AmityWeb2021's avatar
      AmityWeb2021
      Copper Contributor
      Dec 23, 2021

      Yes started last Tuesday for me too. First time I knew about it was 7:30am GMT.

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